Routine proteome analysis using 50 cm μPAC™ columns
The practice of bottom-up proteomics relies to a large extent on the separation performance that can be achieved
with state-of-the art nano LC-MS/MS equipment. Depending on the sample complexity or the instrument time
that can be dedicated to a certain sample, different LC columns and corresponding LC-MS/MS methods are often
required. When aiming for comprehensive proteome analysis with deep coverage, relatively long columns (lengths
up to 75 cm) are typically operated with long and shallow solvent gradients, delivering the highest
chromatographic performance. This is indeed a good strategy if very complex samples need to be analyzed and
when as much information as possible needs to be retrieved from these samples. However, daily routine proteome
analysis often deals with much less complex samples or demands increased sample throughput, making total
analysis times above 120 min undesirable or even impossible.
As an alternative to the conventional packed bed nano LC columns, PharmaFluidics offers micromachined nano LC
chip columns known as micro pillar array columns (μPAC™). The inherent high permeability and low ‘on-column’
dispersion obtained by the perfect order of the separation bed makes μPAC™ based chromatography unique in its
kind. The peak dispersion originating from heterogeneous flow paths in the separation bed is eliminated (no A-term
contributions) and therefore components remain much more concentrated during separation (1). The freestanding
nature of the pillars also leads to much lower backpressure allowing the use of very long columns with exceptional
peak capacities (2).
Complementary to its landmark 200 cm long column which is ideally suited to perform comprehensive and
sometimes time consuming proteome research, PharmaFluidics now also offers a 50 cm long μPAC™ column which
can be used in a more routine research setting. With an internal volume of 3 μL, this column is perfectly suited to
perform high throughput analyses with shorter gradient solvent times (30, 60 and 90 minute gradients) and it can
be used over a wide range of flow rates, between 100 and 2000 nL/min.